btrfs: print assertion failure report and stack trace from the same line

Assertions reports are split into two parts, the exact file and location
of the condition and then the stack trace printed from
btrfs_assertfail(). This means all the stack traces report the same line
and this is what's typically reported by various tools, making it harder
to distinguish the reports.

  [403.2467] assertion failed: refcount_read(&block_group->refs) == 1, in fs/btrfs/block-group.c:4259
  [403.2479] ------------[ cut here ]------------
  [403.2484] kernel BUG at fs/btrfs/messages.c:259!
  [403.2488] invalid opcode: 0000 [#1] PREEMPT SMP KASAN
  [403.2493] CPU: 2 PID: 23202 Comm: umount Not tainted 6.2.0-rc4-default+ #67
  [403.2499] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552-rebuilt.opensuse.org 04/01/2014
  [403.2509] RIP: 0010:btrfs_assertfail+0x19/0x1b [btrfs]
  ...
  [403.2595] Call Trace:
  [403.2598]  <TASK>
  [403.2601]  btrfs_free_block_groups.cold+0x52/0xae [btrfs]
  [403.2608]  close_ctree+0x6c2/0x761 [btrfs]
  [403.2613]  ? __wait_for_common+0x2b8/0x360
  [403.2618]  ? btrfs_cleanup_one_transaction.cold+0x7a/0x7a [btrfs]
  [403.2626]  ? mark_held_locks+0x6b/0x90
  [403.2630]  ? lockdep_hardirqs_on_prepare+0x13d/0x200
  [403.2636]  ? __call_rcu_common.constprop.0+0x1ea/0x3d0
  [403.2642]  ? trace_hardirqs_on+0x2d/0x110
  [403.2646]  ? __call_rcu_common.constprop.0+0x1ea/0x3d0
  [403.2652]  generic_shutdown_super+0xb0/0x1c0
  [403.2657]  kill_anon_super+0x1e/0x40
  [403.2662]  btrfs_kill_super+0x25/0x30 [btrfs]
  [403.2668]  deactivate_locked_super+0x4c/0xc0

By making btrfs_assertfail a macro we'll get the same line number for
the BUG output:

  [63.5736] assertion failed: 0, in fs/btrfs/super.c:1572
  [63.5758] ------------[ cut here ]------------
  [63.5782] kernel BUG at fs/btrfs/super.c:1572!
  [63.5807] invalid opcode: 0000 [#2] PREEMPT SMP KASAN
  [63.5831] CPU: 0 PID: 859 Comm: mount Tainted: G      D            6.3.0-rc7-default+ #2062
  [63.5868] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014
  [63.5905] RIP: 0010:btrfs_mount+0x24/0x30 [btrfs]
  [63.5964] RSP: 0018:ffff88800e69fcd8 EFLAGS: 00010246
  [63.5982] RAX: 000000000000002d RBX: ffff888008fc1400 RCX: 0000000000000000
  [63.6004] RDX: 0000000000000000 RSI: ffffffffb90fd868 RDI: ffffffffbcc3ff20
  [63.6026] RBP: ffffffffc081b200 R08: 0000000000000001 R09: ffff88800e69fa27
  [63.6046] R10: ffffed1001cd3f44 R11: 0000000000000001 R12: ffff888005a3c370
  [63.6062] R13: ffffffffc058e830 R14: 0000000000000000 R15: 00000000ffffffff
  [63.6081] FS:  00007f7b3561f800(0000) GS:ffff88806c600000(0000) knlGS:0000000000000000
  [63.6105] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [63.6120] CR2: 00007fff83726e10 CR3: 0000000002a9e000 CR4: 00000000000006b0
  [63.6137] Call Trace:
  [63.6143]  <TASK>
  [63.6148]  legacy_get_tree+0x80/0xd0
  [63.6158]  vfs_get_tree+0x43/0x120
  [63.6166]  do_new_mount+0x1f3/0x3d0
  [63.6176]  ? do_add_mount+0x140/0x140
  [63.6187]  ? cap_capable+0xa4/0xe0
  [63.6197]  path_mount+0x223/0xc10

This comes at a cost of bloating the final btrfs.ko module due all the
inlining, as long as assertions are compiled in. This is a must for
debugging builds but this is often enabled on release builds too.

Release build:

   text    data     bss     dec     hex filename
1251676   20317   16088 1288081  13a791 pre/btrfs.ko
1260612   29473   16088 1306173  13ee3d post/btrfs.ko

DELTA: +8936

CC: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>